Oil burner nozzle



Sept. 25, 1951 H. J. WISER, SR

OIL BURNER NOZZLE Filed March 13, 1948 INVENTOR. HUBERT J. WISER SR.

BY 47 8 4s ATTORNEV Patented Sept. 25, 1951 OIL BURNER NOZZLE Hubert J.Wiser, Sr., Bloomington, Ill., assignor to Eureka Williams Corporation,Bloomington, 111., a corporation of Michigan Application March 13, 1948,Serial No. 14,731

4 Claims. (01. 299120) 1 This invention relates to oil burner nozzles ofa, kind which is particularly applicable for forming a primary mixtureof fuel and air to be discharged from the nozzle into a secondary airnozzle or passage beyond which the combustible mixture so formed isburned in an oil burner combustion chamber.

An object of the invention is to provide an improved nozzle of this typein which a better atomized and more thoroughly mixed primary mixture canbe formed.

Other and further objects of the invention will be apparent by referenceto the accompanying drawings of which there is one sheet, which, by wayof illustration, shows a preferred embodiment and the principles thereofand what I now consider to be the best mode in which I have contemplatedapplying these principles. Other embodiments of the invention embodyingthe same or equivalent principles may be used and structural changes maybe made as desired by those skilled in the art without departing fromthe present invention and the purview of the appended claims. I alsocontemplate that of the several different features of my invention,certain ones thereof maybe advantageously employed in some applicationsseparate and apart from the remainder of the features.

In the drawing:

Fig. 1 is a fragmentary cross sectional view of an oil burning furnaceshowing a nozzle embracing the principles of the invention and beingillustrated in operative position relative to the secondary air passageor nozzle of the burner and the oil burner combustion chamber;

, Fig. 2 is an enlarged fragmentary longitudinal sectional view throughthe nozzle illustrated by structure disclosed by Fig. 2, except thatFig. 5

is taken substantially on the plane of line 55 on Fig. 2 and illustratesthe front end of the inner tubular body member of the nozzle inelevation. I

Referring particularly to Fig. 1, numeral Ill indicates generally an oilburning furnace hav- 4 ing a combustion chamber II surrounded by a .wallI2.

The wall I2 is provided with an opening indicated at I3 in which issecured an air cone or nozzle member I4 through an orifice I6;

in which secondary air is discharged in a blast into the combustionchamber II. The member I I also is provided with a plurality of circularopenings I'I surrounding the opening I6 through which additionalquantities of secondary air also are discharged into the combustionchamber II around the periphery of the blast of secondary air introducedthrough the nozzle opening I6.

Disposed concentrically with and just inside of the secondary airorifice or nozzle I6 is a primary fuel and air mixing nozzle indicatedgenerally at I8. The nozzle It comprises an outer tubular member body I9containing an inner tubular member or body 2I, the two tubular bodiesbeing adapted to be assembled as a unit and secured by a nut 22 to anair supply conduit 23 projecting from the casing 24 of an oil burnerfuel and air pumping or supply mechanism, only partially shown. The fueland air supply mechanism may be of any suitable type wherein pumpingmechanism is provided for supplying liquid fuel and air to the nozzle I8at relatively low and substantially equal pressures and wherein fan orother suitable means i 'provided for supplying secondary air to thesecondary air nozzle I I which is located about the primary fuel and airmixture nozzle I8. For a more complete description of an oil burnersystem of this type and the primary and secondary air, and the fuelpumping, metering and fan mechanism employed therein, reference may behad to the copending applications for United States Letters Patent ofHoward E. Earl, Serial No. 2,881, filed January 17, 1948, for Oil BurnerSystem, now Patent No. 2,554,491; Howard E. Earl, Serial No. 772,970,filed September 9, 1947, for Motor Compressor Unit, now Patent No.2,542,121; and Robert R. Witherell, Serial No; 13,718, filed March 8,1948, for Oil Burner Pumping Unit.

The liquid fuel referred to is supplied to the nozzle I8 by a conduit 26which is connected to the hollow interior of the inner tubular member 2Iby a tube or conduit 21. A spring 28 disposed about the tube 21 andabutting the adjacent ends of the conduit 26 and the inner tubularmember 2| holds the inner tubular member 2I within the outer tubularmember I9 and in contact with the front end of the latter.

The primary air supply conduit 23 surrounds the fuel supply conduit 26and the tube 21 and supplies primary air to the nozzle I8 through theannular space therebetween. Such air is supplied to the nozzle I8through a plurality of air supply passages indicated at 29, thesepassages being formed between the outer and inner tubular bodies ormembers indicated at l9 and 2| respectively.

Referring particularly to Figs. 2 to 5, the outer body I9 is providedwith a front wall 3| in which a knife-edge orifice indicated at 32 isconcentrically formed. The orifice 32 forms the extremity of afrusto-conical surface indicated at 33 which provides the interiorsurface of the front wall 3 I.

The inner tubular member 2| is provided with a closed front end 34 froma central portion of which projects a conical tip 36 which extendstoward the orifice 32 in concentric relation thereto. The front end 34comprisesralplanular surface indicated at 31 which:extends'normallywithrespect to the axis of the inner tubular member 2| about the base of thetip-36-and-which is in turn surrounded by an annular tapering seatindicated at 38, which is adapted to engage-and to closely fit theinnentapering surface 33 of the front wall: 3| :of: \the body IS.

(The: annular seat 38iwherr engaging the front zwall'3l in the mannerdescribed divides the front :-endof thenozzle |8:into:a;tip chambers39and an annular-mixing chamber :4! which is formed 6: about. the frontend of the inner tubular member I21 anteriorrelation to the seats-38.:Theannular mixing-chamber 4|: is' formed :between an outer cylindricallsurfacezutformed at'the front of the inner'tubular member 2| and theinner:

cylindricalsurfacet43 OIlthG outer tubular member=|9.' Theremaindenofithe exterior surface of theinnertubuiar memberi'zi isiformedby a plurality' of planular surfaces indicated at 44 which :extend asplanular chords across the inner cylin-w drical surfaceof the outermember l9 and-be- --tween' the ends of-which-are'formed arcuatelongitudinally extending seats indicated at "'46.

Seats 48 divide the spacebetweenthe exterior inner tubular member-2|.Between the passage 41 and the annular mixing chamber 4| are a pluralityof fuel supply ports or passages indicated at48-, and by which latterports or passages fuel is supplied from the passage 41' to the annularchamber. The passages 48 are equallyspaced with respect to one anotherand are onset with respect to the axis of the inner tubular member 2| insuch manner as to have a tangential relation to the annular chamber 4|at the ends of thepassages 48' which communicate with the annularchamber 4|. Theouter ends of the passages 48 communicate with theannular chamber 4| approximately midway between the front and rearendsof the annular chamber 4| and are formed in such a way as to providerelatively sharp knifeedgesover which fuel from the interior ofthemember 2| is suppliedto-the annular-chamber 4|. The *ends of thepassages48 communicate with the annular chamber 4| approximately midwaybetween the central por- -tions ofthe'ends'ofthe air supply passages 29-which also communicate with the annular -chamber 4| .Formed across theannular seat 38 between the annular-chamber 4|and the tip chamber 39*are angle with respect to the annular chamber 4| and therefore have asimilar tangential relation to annular seat 38.

the annular chamber 4 The ends 53 communicate with the: annular chamber4| between the ends ofthepassages 48 and somewhat nearer the The; crosssectional contour of the passages 49 is considerably less than the crosssectional contour of the annular chamber 4|, of the passages 29, and ofthe chamber 39. Under such circumstancesiiair.whichfsmay be supplied bythe spassages 29 :will fiowzinto' the annular chamber -4| and thencewillflow in a plurality ofspiral'paths,

through the passages 49 and into the tip chamber 39. Thepassagesu49beingmuch smaller than the other passages andchambersreferred to, it will be apparent that the velocity of.'the=air in thepassage's 49 a will i be considerably greater than the. velocity of theair in the other passages referred to. Also, due'to'the slope or spiralrelation of the passages 49 to'the annular chamber discharged into thechamber 39. since'the' fluid in all of such passages will rotate in thedirec'tion offering the least resistance, it will be apparent thattheair and liquid fueladmitted' to thean- --nular"chamber" 4| fromthe airand fuel supply passages 29 and, respectively, will rotate'in theannular chamber 4| in a clockwise directiom es the nozzleappears inFigs.4- and 5. For the same -reason,- it will be apparent that the fluiddischarged -by the passages- 49 into the tip chamber "39 also Willrotatein a clockwise direction in the tip 'ohamber' 39,as the'nozzle appearsin Fig; 5.

It will be apparent'from Fig. 4that the'passages 48 are somewhatinclined toward or facing the direction of rotation of "fluid in theannular chamber-4| which will cause the passages to provideparticularlysharp'knife edges over which the liquid fuel'from the passages 48 issupplied to the annular chamber'l l.

Dueto the relation of the ends of the passages 29', 48, and 49whichcommunicate with the annular-mixing chamber4 it will beapparen't'tliat air which is supplied to the annular chamber throughanyone-of the passages 29 will tend to flow across the outer end of anadjacent passage 48 beforereaching'the end of 'the passage 49 the frontof the nozzle I8, it'will be apparent that "the fuel in such mixturewill be required to pass over a plurality of sharp edges before beingdischarged as such primary mixture. These edges include the edges formedat the outer extremities of the passages 48, the edges at the oppositeends of the'passages'fl, and the knife edge of the-oriiice 32. Suchsharp-or knife edges tend to finely divide or atomize' the fuel andhence to thorough- 1y mix the fuel with the air as the fuel and airrotate in the mixing chamber H, as such-fuel and air passes through thepassages-49, as such fuel and air rotate Within the tip chamber 39,-and

as such fuel and air is discharged through the burning primary mixturein the proper ratio to i complete the combustion of the fuel supplied bythe nozzle.

While I have illustrated and described a preferred embodiment of myinvention, it is understood that this is capable of modification, and I2 therefore do not wish to be limited to the precise details set forth,but desire to avail myself of 'such changes and alterations as fallwithin the purview of the following claims.

I claim:

1. An oil burner nozzle comprising an outer tubular body having acircular knife-edge orifice formed coaxially therewith at the front endthereof, an inner tubular body within said out'er'body and having afront end formed-to provide an annular seat disposed in engagement withsaid outer body and being spaced from said outer body on opposite sidesof said seat to provide a tip chamber communicating with said orificeand an annular mixing chamber separated from said tip chamber by saidseat, one of said bodies being formed to provide a plurality of passagesacross said seat between said mixing chamber and said tip chamber, thecross section of said passages being not greater than that of saidannular chamber, said passages being formed in similarly sloped relationto one another and being symmetrically related to said mixing chamberand said tip chamber with the opposite ends of said passages openinginto said mixing chamber and said tip chamber in directions tangentlyrelated to said chambers so as to induce a unidirectional rotation offluid in said mixing chamber and in said tip chamber, air supplypassageways communicating at their forward ends with said annularchamber and through which air supply passageways air under pressure issupplied to said annular chamber, a plurality of spaced oil supply portscommunicating between the interior and exterior of said inner tubularbody and in advance of the passage ends in said annular chamber andthrough which oil supply ports-oil is supplied for mixture with the airsupplied through said air supply passageways, said oil supply portsdischarging jets of oil into said air in advance of the passage ends insaid annular chamber, said nozzle construction being such that oil ismixed with air and such mixture is rotated in said annular chamber andin flowing from said annular chamber into said passages such mixturebreaks over the edges of said passages and changes directions, and suchmixture further breaks over the edge of said orifice and changesdirection in passing from said tip chamber through said orifice.

2. An oil burner nozzle according to claim 1 in which the front end ofsaid inner tubular body is provided with a conical tip projecting towardsaid orifice and disposed concentrically with respect thereto, saidpassage ends projecting into '6 said tip chamber in a direction so. asto project a mixture of oil and air toward a wall of said tip chamberopposite said conical tip whereby said mixture will whirl around saidtip chamber and break over the knife edge thereof.

' 3. An oil burner nozzle comprising an outer tubular body having acircular knife-edge orifice formed coaxially therewith at the front endthere.- of, an inner tubular body within said outer body and having afront end formed to provide an annular seat disposed in engagement withsaid outer body and being spaced from said outer body Eon opposite sidesof said seat to provide a tip chamber communicating with said orificeand'an annular mixing chamber separated from said tip chamber bysaidse-at, said front end of said inner ,tubular'body having a conicaltip projecting to.- ward said orifice and concentrically with respectthereto, .one of said bodies being formed to provide a plurality ofpassages across'said seat between said mixing chamber and said tipchamber, the cross section of said passages being materially less thanthat of said annular chamber,

said passages being formed in similarly sloped relation and beingsymmetrically related to said mixing chamber and said tip chamber withthe opposite ends of said passages terminating within said mixingchamber and said tip chamber, .said passage ends opening into each ofsaid cham- -bers in directions tangently related to said chambers soas-to induce a unidirectional rotation of fluid in said mixing chamberand said tip chamber, a plurality of spaced oil supply portscommunicating between the interior of said inner tubular body and saidannular chamber and through which oil supply ports oil is supplied tosaid annular chamber, said ports having a relation to said annularchamber forming relatively sharp edges across the line of flow of fluidin said annular chamber, said sharp edges being positioned between theopposite ends of said annular chamber and in advance of said passageends in said annular chamber, said inner body on the side of saidannular chamber remote from said, annular seat being formed to provide aplurality of seats engaging the interior of said outer body for dividingthe space between said inner and outer bodiesinto a plurality oflongitudinally disposed air supply passageways communicating at theirforward ends with said annular chamber, and through which air supplypassageways air under pressure is supplied to said annular chamber, saidoil supply ports communicating with said annular chamber between saidforward ends and said passage ends and discharging jets of oil into theair supplied through said air supply passageways, said nozzleconstruction being such that oil is mixed with air in said annularchamber and such mixture breaks over the edges of said passages andchanges direction in flowing from said annular chamber into saidpassages and is projected toward a wall of said tip chamber, and suchmixture further breaks over the edge of said orifice and changesdirection in passin from said tip chamber through said orifice.

4. An oil burner nozzle comprising an outer tubular body having acircular knife-edge orifice formed coaxially therewith at the front endthere of, an inner tubular body within said outer body and having afront end formed to provide an annular seat disposed in engagement withsaid outer body and being spaced from said outer body on opposite sidesof said seat to provide a tip chamber communicating with said orificeand an annular mixing chamber separated from said tip annular "chamber;said oilsupply ports communiliiai'nber bysaid seatj said front 'en'd"tubular body having a-"conical" .tip Jprojectin'g.:to-

wird said orifice and concentricallywith respect thereto; one-o1 i saidbodies bein'g'formed to provide a plurality -ot' passages across saidseat'bet'weensaid mixing chamber and'said tip. chamber,

' the cross section of saidpassages being materially than that of-saidannulanehambensaidpas- 'iages' 'being formed in similarly sloped'relation andbeing' symmetrically related to 'saidmixin ol'iamber' andsaidl tip chamber with the opposite ends of said passages terminatinginxequally mg between the'interior of said inner tubular body =lndsaidannular chamber and opening into'asaid annular :chamber "between theopposite ends of said I annular chamber and in advance of said passageendsinsaid annular chambensaidinner body on the side ot'said annularchamber remote Jfiom saidannular seat being formed to providelongitudinally disposed seats engaging'the interior 0!" said outer bodyfor dividing the space between -saidfinner'and outer bodies intoapluralityof Jongitudinally 1 disposed I air supply passagewaysPeomrnuhicating at their forward ends with: said eetingw-ithsaid annularchamber between said forward ends and saidpassage ends and dis- ChargingJetsof oil into the'air supplied through flidair supply-passageways,said nozzle construction being such that oil is mixed with air in saidannular chamber andsuch mixture breaks over theedges of said passagesand changesdirection in'i'iowingfrom saidannular chamber into said"pessages andsuch mixture further breaks over the edgeiof saidorifice-and changes direction in ipassing from said tip chamber throughsaid oriflee.

HUBERT J. WISER. Sn.

-REFERENCES CITED The following references are of record in the me ofthisapatent:

UNITED STATES PATENTS "Number Name Date --1,227,-867 Young May 29, 19175153345755 Wil1ilatms. Nov. 14, 1933 2,055,864 Harsch s Sept. 29,-19362,249,482 Macchi July 15,4941 2,284,264 Crisp May 26, 1942 FOREIGNPATENTS Number Country Date 82,573 Sweden June 28, 1932

